John c



(No Model.)

J. O. STEVENS.

BOOK DRILLING MACHINE.

No. 371,800. Patented Oct. 18, 1887.

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JOHN G. STEVENS, OF PORT CHESTER, NEW YORK, ASSIGNOR TO NATHAN O. POND,MARSHALL 0. WEST, AND ERNEST SIMONS, ALL OF SAME PLAOE.

ROCK- -DRILLING MACHINE,

SPECIFICATION forming part of Letters Patent No. 371,800, dated October18, 1887.

Application filed January 25, 1887. Serial No. 225,435. (No model.)

To all whom, it may concern.-

Be it known that I, JOHN G. STEVENS, a citizen of the United States,residing at Port Chester, in the county of Westchester and State of NewYork, have invented certain new and useful Improvements in Rock-DrillingMachines; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

This invention relates, in general, to that class of rock-drillingmachinesin which a drillcarrying shaft is caused to reciprocatelongitudinally to drive the drill by successive thrusts into the rock,and it particularly relates to improvements in the Ingersoll rockdrill,patented July 5, 1856, and numbered 344,906.

The object of the invention is to produce a simpler machine with fewerworking parts and with parts not so liable to be broken.

To this end the invention consists in mech anism for raising the drillagainst the resistance ofa spring, in means for defending the machinefrom injury by wild blows, and in means whereby the amount of the said,raising may be graduated proportionally to the blow or thrust requiredin dilTerent kinds of work to be done by the machine, as hereinafterdescribed and claimed, reference being had to the accompanying drawings,in which-- Figure 1 is a section, part in side elevation, of arock-drilling machine showing myinvention; and Fig. 2 is a rear or underside view of the cam-wheel and beveled gears and a portion of the frameand carriage.

4 represents the frame of the machine, mounted, as usual, upon a tripodof adjustable legs, 5.

6 is the drill, carried by a drill-shaft, 7,which' isjournaled to rotateand to reciprocate longitudinally in a carriage, 8, which is fitted-toslide on the frame 4: when fed along by hand or automatically by ascrew, as usual.

9 is a spring which thrusts the drill-shaft forward or downward in theact of drilling.

10 is a cam-wheel provided with bevel gearteeth and journaled upon astud, 11, which is fixed in the carriage 8, and the arms 12 of this Caneengage a roller, 13, mounted on a stud, 19, which projects from thecross-head 20, that is fixed to the drill-shaft 7, the stud 19 beingparallel with the stud 11. The cams act to ter of the cam-wheel, wherebyeach revolution of the cam-wheel raises the drill as many times as thereare arms 12, the spring 9 throwing down the drill as soon as the roller13 leaves the inner end of each arm.

14 14 represent beveled gear-wheels journaled on independent studs firedin the carriage 8, to engage the oppositeedges of the cam-wheel 10, andprovided with cranks 15, whereby the operator is enabled to operate themachine while standing at either side thereof, or he may stand either tothe. front or rear thereof and turn both cranks 15 at once in oppositedirections to operate the machine. The cranks may be set to both hangdown at once, in which case the operator may exert his strength withoutmoving the machine bodily either way and without being forced off fromhis base, because he pushes with one hand and pulls with the other; butif the object be to maintain the machine as rigidly as possible in itsposition against-a twisting strain, then the cranks should be setopposite each other, one up while the other is down, so that both mustbe pulled upon or both be pushed upon at the same time.

To adapt this machine to strike blows of Varying degrees of force, Imake the arms 12 adjustable as follows: 16 is a pivot-bolt by which theouter end of the arm 12 is secured to the cam-wheel, and each arm isprovided with one or more slotted segmental ears, 17, concentric withthe pivot 16, and screw-bolts 18 pass through these slotted segments andinto the cam-wheel, whereby the cams may be swung into differentpositions, as shown in dotted lines, and then be rigidly secured to thecam-wheel in any such position. The nearer the inner end of an arm isset to the center of the cam-wheel the higher the drillwill be liftedthereby, and, the spring being more com pressed, the more forcible willbe the blow,

and vice versa,

draw the drill-shaft up axially toward the cen- 55 To prevent jar anddamage to the machine in case it is operated when there is nothing toreceive the force of the blow-such blows when made being termed wildblowsI hax e provided buffers or cushions 20, fixed on some stationaryportion of the carriage 8-such as the lower cross-bar thereof-to receivethe cross-head 21 when the spring throws it a little beyond its normalpath. There may be one or more such cushions, and I prefer soft rubberas the material therefor.

The drill-shaft 7 maybe intermittently rotated to give the bit or drilla new cut at each stroke by any usual means-such as a spiral slot in thedrill-shaft engaged by a feather fixed in a ratchet-wheel, 23, which iskept from revolving in one direction by the usual spring-paw], but iscaused to revolve in the other direction a part-of a circle at a time bythe vertical motion of the shaft. By this means the vertical motion ofthe shaft in one direction rotates the ratchet, and the vertical motionthereof in the opposite direction rotates the drillshaft, because theratchet is held still at its last stopping-place.

I do not suppose or claim this device to be a new mechanical movementfor converting continuous rotary motion into reciprocating rectilinearmotion. The cranks, the bevelgears, the cams, the reciprocating shaft,and

the cushions or buffers are common devices when used singly for similarpurposes.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The combination, in a roclcdrilling machine, of a drill-carriage, adrill-shaft journaled to reciprocate therein and provided with astud anda roller on it projecting from its side, a cam-wheel journaled on astud. fixed in the drill-carriage parallel with the said rollerstud, andone or more cam-shaped arms pivoted at one end of each to the cam-wheelnear its edge and adj ustably secured at the other end to the cam-wheel,substantiall y as shown and described.

2. The combination, in a rock-drilling machine, of the cam-wheel 10, thecam-shaped arms 12, provided with slotted segmental ears 1 17, thepivot-bolts 11 and 18, securing the cam-arms 12 to the cam-wheel, andthe drillshaft 7, provided with a stud and roller, 13, adapted tobeengaged by the said cam-arms, substantially as shown and described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN G. STEVENS.

\Vitnesses:

STEPHEN A. MARSHALL, JOHN E. MARSHALL.

